Biodegradable dry cleaning solvent

ABSTRACT

A method of dry-cleaning garments which comprises treating the garments with a mixture of propylene glycol tertiary-butyl ether or propylene glycol n-butyl ether and water.

CROSS REFERENCE TO RELATED APPLICATION

This application is a 371 of PCT/US98/06811 filed Apr. 6, 1998, which isa C-I-P of U.S. patent application Ser. No. 08/833,341 filed Apr. 4,1997, now U.S. Pat. No. 5,888,250.

TECHNICAL FIELD

The present invention relates to a novel dry-cleaning solvent and amethod for effecting dry-cleaning using said solvent. More particularly,the present invention relates to a solvent which is comparable orsuperior to perchloroethylene in its attributes and benefits, but whichdoes not suffer from the serious environmental, health and occupationalnegatives and problems associated with the use of perchloroethylene.

BACKGROUND ART

The most widely used dry-cleaning solvent is perchloroethylene, which iscommonly referred to and will be referred to sometimes hereinafter as("Perc"), which is a chlorinated hydrocarbon-based solvent. It is thedry-cleaning solvent of choice throughout North America, Europe andAsia.

In addition to Perc's use in the dry-cleaning industry, it has foundextensive use as a degreasing agent in the metals industry, inscouring/milling and in various "clean room" applications in thesemiconductor and electronics industry. The industrial uses of Perc areapproximately tenfold greater than its use as a solvent fordry-cleaning.

While Perc has been found to be an effective dry-cleaning agent due tothe fact that it does not damage synthetic fabrics or cause shrinkage tofabrics containing naturally occurring fibers, such as wool, as well asbeing non-flammable and possessed of a relatively low boiling point,which permits its being reclaimed and purified by means of ordinarydistillation, it does present a number of other problems which presentdrawbacks to its use.

In particular, perchloroethylene presents a number of health andenvironmental hazards which would militate against its continued use,provided a substitute solvent of comparable quality were available whichwere free of the aforementioned hazards.

Since Perc is heavier than water, its disposal represents a significantenvironmental risk since it will sink to the bottom of the aquifer,lake, river, etc., with possibly resultant contamination of the watersupply. Additionally, Perc vapors have been implicated as having adeterious effect on the central nervous system. In addition, due to itsbeing a highly chlorinated molecule, Perc has been identified as being asignificant health hazard to cattle, and as a cause of skin cancer,particularly melanoma, due to the action of the chlorine in Percdepleting oxygen from the ozone layer. Furthermore, and of particularimport, is the fact that Perc is not biodegradable and, hence, will,over a period of time accumulate, presenting a significant industrialwaste disposal hazard.

As the nature and seriousness of the foregoing problems became more andmore manifest with the passage of time and with the completion ofvarious research and clinical investigations into the nature of Perc andits mechanisms of action, the use of alternative solvents has beensought, but none have met with any degree of commercial success sincethey could not match the results obtained by Perc as a dry-cleaningagent.

However, at this point in time, when environmental concerns are beingrigorously monitored and policed by domestic and foreign governments bymeans of legislation and civil and even criminal prosecution, the needfor a substitute solvent for Perc for dry-cleaning operations, as wellas other operations, has become a matter of some degree of urgency.

A difficulty in identifying a replacement dry-cleaning solvent for Percis that it must meet so many requirements, both as to its efficacy as adry-cleaning agent, i.e., non-shrinking with respect to about 160 typesof fabric, dye-fast for non-bleeding with respect to about 900 types ofdyes, a high flashpoint to render it non-flammable and non-combustible,the ability to separate from water, effective detergency, distillable,reclaimable, usable with existing dry-cleaning equipment, etc., as wellas its being non-polluting to the water supply and the ozone layer,biodegradable, non-toxic, non-carcinogenic, etc.

One proposed solvent substitute, namely, propylene glycol monomethylether, which is disclosed in EP 479,146 A2 as possessing many desirableproperties, was found to be wanting in that it causes damage to weakdyes and to fine yarns and to delicate fabrics, such as acetates, due toits pronounced tendency to accumulate water. Water accumulation orwater-miscibility is also a decided negative from another aspect in thatit significantly impairs the efficiency of the dry-cleaning processsince the dry-cleaning equipment is burdened with the handling ofexcessive quantities of water and the solvent stock is diluted and mustbe brought back to a correct ratio for stability reasons.

SUMMARY OF THE INVENTION

In line with the foregoing, it is an object of the present invention toprovide a solvent which possesses comparable, if not superior chemicaland physical properties when compared to Perc in dry-cleaning,degreasing of metals, cleaning of electronic components and the scouringand milling of woolens, while, simultaneously, protecting theenvironment, public health and safety from the many known negativesassociated with the use of Perc.

It is a further object of the present invention to provide adry-cleaning solvent which has a specific gravity less than that ofwater.

It is still a further object of the present invention to provide adry-cleaning solvent which minimizes or eliminates shrinkage of woolengarments, prevents or limits the bleeding of dyes, and which is able totreat acetates, silks, virgin wool and other delicate fabrics gently soas to avoid damage.

It is still another object of the present invention to provide adry-cleaning and degreasing solvent which is non-flammable and which hasa sufficiently low boiling point to allow it to be reclaimed andpurified via conventional distillation processes.

It is still yet another object of the present invention to provide a dyesolution containing dyes that are not water-soluble in a solvent thatminimizes or eliminates shrinkage of woolen fabrics and does not damageacetates, silks, virgin wool and other delicate fabrics that penetratesthe fabric fibers sufficiently to form a strong dye bond to fabricfibers.

Therefore, according to one embodiment of the present invention, adry-cleaning composition is provided containing:

a solvent selected from the group consisting of propylene glycoltertiary-butyl ether and propylene glycol n-butyl ether;

an amount of water up to the maximum quantity soluble in the solvent atroom temperature; and

a fabric softening agent in an amount effective to soften the fabric ofgarments cleaned with the dry-cleaning composition.

The preferred solvent is PTB in a composition containing up to about 18percent by weight of water and at least 82 percent by weight of PTB. Thedry-cleaning compositions of the present invention absorb water from thegarments being dry cleaned. The ability to absorb water increases, asthe temperature of the composition increases, so that even compositionsthat are moisture saturated at room temperature will absorb water fromgarments when heated. The water is then separated from the solvent byazeotropic distillation, with the recovery of essentially pure PTB orPNB.

Therefore, the present invention also includes a method for dry-cleaninggarments using the dry-cleaning compositions of the present invention.Methods in accordance with this embodiment of the present inventiontreat the garments in a composition containing a solvent selected frompropylene glycol tertiary-butyl ether and propylene glycol n-butylether, and an amount of water up to the maximum quantity soluble in thesolvent at room temperature, for a period of time sufficient to effectdry-cleaning.

The dry-cleaning compositions of the present invention can also be usedto clean scoured and milled wool. Methods in accordance with thisembodiment of the present invention treat the scoured and milled woolwith a dry-cleaning composition containing a solvent selected frompropylene glycol tertiary-butyl ether and propylene glycol n-butylether, and an amount of water up to the maximum quantity soluble in thesolvent at room temperature, to effect cleaning.

The dry-cleaning compositions can also be used in the wool scouring andmilling processes as well. In accordance with this embodiment of thepresent invention, a method of scouring wool is provided characterizedby scouring the wool with a composition containing a solvent selectedfrom propylene glycol tertiary-butyl ether and propylene glycol n-butylether, and an amount of water up to the maximum quantity soluble in thesolvent at room temperature. The solvent compositions of the presentinvention cleanly dissolve the lanolin contained in the raw wool forsubsequent recovery and purification for use as an ingredient incosmetics and other products.

According to another embodiment of the present invention, a method isprovided for milling wool, characterized by milling the wool with acomposition containing a solvent selected from propylene glycoltertiary-butyl ether and propylene glycol n-butyl ether, and an amountof water up to the maximum quantity soluble in the solvent at roomtemperature.

The present invention further incorporates the discovery thatwater-insoluble dyes that are soluble in aliphatic glycol ethers aresoluble in the dry-cleaning compositions of the present invention, toprovide dye compositions that may be used to dye non-woolen fabrics withsignificantly improved colorfastness. The drying times of fabrics dyedwith the dye compositions of the present invention is significantlydecreased as well, yet at the same time, a stronger bond between the dyemolecules and the fabric fibers is formed.

Therefore, according to another aspect of the present invention, acomposition for dyeing fabrics is provided that is a solution of analiphatic glycol ether-soluble dye dissolved in a mixture of a solventselected from propylene glycol tertiary-butyl ether and propylene glycoln-butyl ether, and an amount of water up to the maximum quantity solublein the solvent at room temperature.

According to yet another embodiment of the present invention, a methodis provided for dyeing fabric with the dye compositions of the presentinvention. Methods in accordance with this aspect of the presentinvention treat the fabric for a period of time sufficient to effectdyeing with a dye composition containing a solution of an aliphaticglycol ether soluble dye dissolved in a solvent selected from propyleneglycol tertiary-butyl ether and propylene glycol n-butyl ether, and anamount of water up to the maximum quantity soluble in the solvent atroom temperature. Methods in accordance with the present inventionfurther include the step of drying the fabric after the step of treatingthe fabric to effect dying is completed.

Other features of the present invention will be pointed out in thefollowing description and claims, which disclose the principles of theinvention and the best modes which are presently contemplated forcarrying them out.

BEST MODE OF CARRYING OUT THE INVENTION

It has been found that when propylene glycol tertiary-butyl ether (PTB)and propylene glycol n-butyl ether (PNB) are used in the dry-cleaning ofgarments, both solvents possess all of the attributes associated withperchloroethylene and none of its drawbacks. Furthermore, both propyleneglycol tertiary-butyl ether and propylene glycol n-butyl ether also havecertain significant advantages not possessed by perchloroethylene. Forinstance, by using a mixture of either PTB or PNB and water, the watercomponent is effectively tied-up, thus avoiding the tendency of woolengarments to shrink in water, while simultaneously preventing damage toacetates. Further, the water component lowers the solvent boiling pointsand raises the flashpoints.

It has also been determined that solutions of PTB or PNB and water areeffective in the cleaning of scoured and milled raw wool, as well as inthe scouring of the raw wool, which involves the pulling of oils andfatty acids, e.g., lanolin, from wool and in the milling of the yarnsformed therefrom. Such scouring and milling operations are conducted indry-cleaning machinery employing otherwise conventional scouring andmilling techniques.

A particular advantage of other PTB-water and PNB-water mixtures of thepresent invention in dry-cleaning is that they do not behave like atypical mixture, but, rather, their behavior is the same as a singlesubstance. This permits a better defined separation upon azeotropicdistillation at a lower boiling point and also facilitates reclamationmore effectively, at a level of 99 percent or greater, and also enhancespurification using conventional distillation techniques.

Of particular note, from an economic as well as an operationalstandpoint, is the ability of PTB and PNB to separate from water byazeotropic distillation. This is of particular significance indry-cleaning since garments entering a dry-cleaning plant contain waterin the form of moisture. If water were not separable from the PTB or PNBsolvent, by azeotropic distillation, the solvent would be diluted withfree water and, thus, the dry-cleaning process, and its efficiency,would be seriously compromised, as would the reclaimability of the PTBor PNB.

From the perspective of performance, the PTB and PNB will enhance theability to dry and clean woolen and cotton garments since those types ofgarments will be subjected to little, if any, shrinkage due to the factthat PTB and PNB have a limited degree of miscibility with water.Additionally, this limited degree of miscibility avoids dilution of thesolvent stock with its attendant problems, which are not inconsiderablewhen one considers the need to replenish the solvent.

PTB and PNB are very effective dry-cleaning solvents since theirdetergency action breaks down solvent-soluble stains, which account for15 percent of all stains found in garments and which are caused by fattyacids. The detergency of the solvent occurs by lifting the soiled areafrom a surface and by displacing it with surface active materials thathave a greater affinity for the surface than they do for the soiledarea. It can also deal most effectively with water-soluble stains, whichaccount for more than 80 percent of stains encountered in dry-cleaning,such as, for example, stains from fruit, blood, urine, sweat, etc. Ithas also been found to limit the bleeding of dyes and to avoid theshrinkage of man-made polymers, such as acetates.

From the standpoint of health and safety, which, as previouslymentioned, are of significant importance in the present era, thecompositions of the present invention containing PTB and PNB arenon-flammable, non-combustible, non-carcinogenic, non-toxic and, of theutmost import, biodegradable. The compositions weigh less than water,i.e., the specific gravity is less than that of water.

The compositions of the present invention containing PTB and PNB dry ata relatively low temperature, namely, about 55° C., which is well withinthe drying requirements for fabrics constructed of fine yarns so as toavoid damage thereto by excessive heat.

In preparing the compositions of the present invention, either PTB orPNB and water are combined with an amount of water up to the maximumquantity soluble in the PTB or PNB at room temperature. If necessary,water may be added to the PTB or PNB to obtain the desired ratio ofsolvent and water. Greater than about 18 percent by weight of water willresult in the shrinkage of woolen garments, or, conversely, if thequantity of PTB or PNB is increased, damage to acetate fabrics canoccur, accompanied by increased bleeding of dyes. It is thereforepreferable that the quantity of PTB or PNB be maintained at less than 90percent by weight, and even more preferably less than 85 percent byweight. At those percentages, it is still an effective dry-cleaningsolvent. Most preferably, as stated previously, is the use of about 82percent by weight of PTB and about 18 percent by weight of water, whichprovides the best dry-cleaning results combined with the most efficientand cost-effective dry-cleaning operation.

While PTB and PNB can quite successfully and efficiently clean garmentsmade of all types of textile fabrics without the need for additionalagents, such as detergents and fabric softeners, it is desirable toinclude in the formulation one or more surfactants to enhance thedetergency action of the PTB or PNB, by means of reducing the surfacetension of the composition. Exemplary surfactants are fatty alcoholpolyethylene glycol ethers and linear primary alcohol ethoxylates. Whilefabric softening agents are not necessary to achieve effectivedry-cleaning, they are beneficial and serve to enhance the dry-cleaningprocess.

It has also been determined that the mixtures of PTB or PNB and water ofthe present invention are effective solvents for water-insoluble dyesand the dyeing of fabrics. Dye compositions can be prepared bydissolving aliphatic glycol ether-soluble dyes in the mixtures of PTB orPNB and water of the present invention. Dyes that are water-insolublebut soluble in aliphatic glycol ethers can be readily identified bythose of ordinary skill in the art without undue experimentation byperforming simple solubility testing. Classes of water-insoluble dyesinclude basic or cationic dyes, dispersed dyes and vat dyes. Dyecompositions are prepared by mixing an effective amount of the dye witha heated mixture of PTB or PNB and an amount of water up to the maximumquantity soluble at room temperature until the dye is completelydissolved in the mixture of PTB or PNB and water.

Fabric dyeing can be conducted using conventional dyeing equipment, orby using dry-cleaning machinery. The mixture of PTB or PNB and water notonly functions to dissolve the dye, it also promotes the penetration ofthe dye into the fabric fiber to form a stronger bond between the dyemolecule and the fabric fiber.

After the dyeing is completed, the fabric is dried by essentiallyconventional techniques. Fabrics dyed with aliphatic glycolether-soluble dyes dissolved in a mixture of PTB or PNB and waterexhibit faster drying times than fabrics dyed with water-based dyes.However, the greatest advantage is that the mixtures of PTB or PNB andwater permit the use of water-insoluble dyes to dye fabrics that arecolorfast when the dyed fabrics are subsequently washed in water.

The following examples are set forth to illustrate more clearly theprinciple and practice of the present invention. It is to be understood,of course, that the invention is not limited to the specific examples.

EXAMPLE 1

One of the most significant properties that a dry-cleaning solventshould possess is limited fiber shrinkage to ensure that fiberscomprising the garment do not shrink excessively. Excessive shrinkage,naturally, deforms the garment rendering it unsuitable for future wear.Accordingly, the dry-cleaning solvent which is employed must notexcessively shrink the component fibers which comprise the fabric of thegarment. In contemporary usage, garments containing virgin wool andacetates, such as the lining found in men's jackets, can ill-affordshrinkage beyond established norms.

A shrinkage test was conducted with respect to virgin wool by taking aseries 4"×4" patterned virgin wool swatches and immersing them inseparate containers containing each of the azeotropic solvents set forthin Table I below. Approximately 10 minutes of mechanical action wasapplied to ensure that the wool fibers became totally saturated. Thetest swatch was then removed and dried at a constant temperature notexceeding 55° C. The test swatch was then compared with a controlmaterial to identify any changes in the fibers to ensure that thepatterns had not changed their dimensions.

Each of the test solvents was then analyzed to identify any fiber loss.The maximum shrinkage should not exceed 2 percent on the first immersiontest and is usually expected to be less than 0.25 percent in anysubsequent immersion test.

                  TABLE I                                                         ______________________________________                                                              % Shrinkage                                             Solvent               On 1.sup.st  Immersion                                  ______________________________________                                        PM (propylene glycol methyl ether)                                                                  2%                                                      PNP (propylene glycol n-propyl ether)                                                               2%                                                      DPM (dipropylene glycol methyl ether)                                                               2%                                                      PERC (perchloroethylene)                                                                            2%                                                      PTB (propylene glycol tertiary-butyl ether)                                                         1/2%                                                    ______________________________________                                    

EXAMPLE 2

The shrinkage test conducted in Example 1 was repeated with 4"×4"swatches of acetate fabric. The results are set forth below in Table II,wherein it is evident from an examination of the results therein, and inTable I, that propylene glycol tertiary-butyl ether mixtures resulted inthe smallest percentage of shrinkage in both virgin wool and acetatefabrics and, in fact, reduced shrinkage by about 400 percent or greatercompared with the other solvents, including Perc, when employed withvirgin wool, and an even greater percentage when employed with acetatefabrics.

                  TABLE II                                                        ______________________________________                                                              % Shrinkage                                             Solvent               On 1.sup.st  Immersion                                  ______________________________________                                        PM (propylene glycol methyl ether)                                                                  3%                                                      PNP (propylene glycol n-propyl ether)                                                               3%                                                      DPM (dipropylene glycol methyl ether)                                                               2-5%                                                    PERC (perchloroethylene)                                                                            2%                                                      PTB (propylene glycol tertiary-butyl ether)                                                         1/2%                                                    ______________________________________                                    

EXAMPLE 3

The bleeding of dyestuffs is the bane of the dry-cleaners existence. Thevariety of dyestuffs, their differing chemical structures, the degree towhich they are soluble or insoluble in the particular dry-cleaningsolvent employed, etc., present manifold problems which must be met,addressed and solved before a new dry-cleaning solvent can be introducedsuccessfully.

Dye-bleeding tests were conducted by taking test swatches of virginwool, 1"×1", and immersing them in separate containers filled with eachof the azeotropic solvent mixtures indicated in Table III below. Ballbearings were added to each of the containers to increase the impact ofmechanical action on the dyes in an effort to dislodge the dyes from thefabric. The increased mechanical action was applied for a period of 10minutes. Thereafter, the test swatch and the ball bearings were removedfrom the solvent. Colorimeter tests employing a Bausch Lomb Spec-20calorimeter were conducted on the solvent remaining, which serves toindicate the relative quantity of dye removed by the test swatch. Theresults are set forth below in Table III with respect to the varioussolvents tested on virgin wool swatches which had been dyed red, green,yellow, blue and purple, respectively. The greater the value, thegreater the degree of dye-bleeding.

                  TABLE III                                                       ______________________________________                                        DYE BLEEDING                                                                  Solvent Red      Green   Yellow  Blue Purple                                  ______________________________________                                        PM      8        7       7       8    8                                       PNP     6        4       4       5    6                                       DPM     6        3       5       5    6                                       Perc    2        2       1       1    3                                       PTB     2        1       1       2    1                                       ______________________________________                                    

EXAMPLE 4

In similar fashion to Example 3 above, swatches of various coloredacetate fabrics were tested to determine dye bleeding in thebelow-listed solvents. The results are set forth in Table IV below.

                  TABLE IV                                                        ______________________________________                                        DYE BLEEDING                                                                  Solvent Red      Green   Yellow  Blue Purple                                  ______________________________________                                        PM      9        8       9       9    8                                       PNP     9        8       8       8    8                                       DPM     8        8       8       9    8                                       Perc    1        1       1       2    2                                       PTB     2        1       1       2    2                                       ______________________________________                                    

It is clearly evident from Tables III and IV that the azeotropic solventof the present invention, namely, propylene glycol tertiary-butyl ether(PTB), is far superior to PM, PNP and DPM, and is comparable to Perc, asrespects dye bleeding, whether the fabric employed is virgin wool oracetate. In point of fact, the solvent of the present invention was ineach instance, regardless of fabric type or dye color, significantlymore effective in preventing the bleeding of dyes when compared with thenon-Perc solvents.

EXAMPLE

                  TABLE V                                                         ______________________________________                                        TYPE OF STAIN PERC W/SOAP PTB W/O SOAP                                        ______________________________________                                        Shoe Polish   50%         50%                                                 Lipstick      60%         70%                                                 Face Powder   100%        100%                                                Ketchup       40%         70%                                                 Salad Dressing                                                                              70%         80%                                                 Animal Fat    80%         80%                                                 Mascara       90%         90%                                                 Mayonnaise    90%         90%                                                 Coffee        30%         60%                                                 Ink           30%         40%                                                 Motor Oil     80%         80%                                                 Syrup         80%         90%                                                 ______________________________________                                    

It is evident with respect to each of the stains enumerated, which arequite typically encountered by dry-cleaners, that the PTB and PNBcompositions of the present invention performed as well as or betterthan Perc, which is the most prevalent solvent employed in dry-cleaningtoday.

STATEMENT OF INDUSTRIAL APPLICABILITY

The compositions and methods of the present invention are useful in thedry-cleaning of garments, the scouring and milling of raw wool and thedyeing of fabrics with water-insoluble, aliphatic glycol ether-solubledyes. As will be readily appreciated, numerous variations andcombinations of the features set forth within the foregoing descriptionand examples can be utilized without departing from the presentinvention.

The foregoing examples are intended to be illustrative only and are notto be deemed as in any way limiting the scope of the appended claims.

What is claimed is:
 1. A composition for dry-cleaning garments,comprising propylene glycol tertiary-butyl ether (PTB), up to about 18%by weight of water and a fabric softening agent in an amount effectiveto soften the fabric of garments cleaned with the dry-cleaningcomposition.
 2. The composition of claim 1, characterized by thepropylene glycol tertiary-butyl ether being present at a level of aboutat least 82 percent by weight.
 3. The composition of claim 2,characterized by the propylene glycol tertiary-butyl ether being presentat a level no greater than about 90 percent by weight.
 4. Thecomposition of claim 1, further characterized by an effective amount ofa surfactant.
 5. A composition for dry-cleaning garments, comprisingpropylene glycol n-butyl ether (PNB), up to about 18% by weight ofwater, and a fabric softening agent in amount effective to soften thefabric of garments cleaned with the dry-cleaning composition.
 6. Thecomposition of claim 5, further characterized by an effective amount ofa surfactant.
 7. A method of dry-cleaning garments, comprising treatingthe garments for a period of time sufficient to effect dry-cleaning in adry-cleaning composition comprising propylene glycol tertiary-butylether (PTB) and up to about 18% by weight of water.
 8. A method ofdry-cleaning garments, comprising treating the garments for a period oftime sufficient to effect dry-cleaning in a dry-cleaning compositioncomprising propylene glycol n-butyl ether (PNB) and up to about 18% byweight of water.
 9. The method of claim 7 or 8, characterized in thatthe period of time is sufficient to remove solvent-soluble andwater-soluble stains.
 10. The method of claim 7, characterized in thatsaid propylene glycol tertiary-butyl ether is present in saiddry-cleaning composition at a level of at least about 82 percent byweight.
 11. The method of claim 10, characterized in that said propyleneglycol tertiary-butyl ether is present in said dry-cleaning compositionat a level no greater than about 90 percent by weight.
 12. The method ofclaim 7 or 8, characterized in that said dry-cleaning compositionfurther comprises a fabric softening agent present in an amounteffective to soften the fabric of the treated garments.
 13. The methodof claim 7 or 8, characterized in that said dry cleaning compositionfurther comprises a surfactant.
 14. A method of cleaning scoured andmilled wool, comprising treating the scoured and milled wool with acomposition to effect cleaning, said composition comprising propyleneglycol tertiary-buty ether PTB) and up to about 18% by weight of water.15. A method of cleaning scoured and milled wool, comprising treatingthe scoured and milled wool with a composition to effect cleaning, saidcomposition comprising propylene glycol n-butyl ether (PNB) and up toabout 18% by weight of water.
 16. The method of claim 14, characterizedin that said propylene glycol tertiary-butyl ether is present in saidcomposition at a level of at least about 82 percent by weight.
 17. Themethod of claim 16, characterized in that said propylene glycoltertiary-butyl ether is present in said composition at a level nogreater than about 90 percent by weight.
 18. The method of claim 14 or15, characterized in that said dry cleaning composition furthercomprises an effective amount of a surfactant.
 19. A composition fordyeing fabrics comprising a solution of a water-insoluble dye that issoluble in an aliphatic glycol ether and is selected from the groupconsisting of cationic dyes, dispersed dyes and vat dyes, dissolved in asolvent comprising propylene glycol tertiary-butyl ether (PTB) and/orpropylene glycol n-butyl ether (PNB) and up to about 18% by weight ofwater.
 20. The composition of claim 19, wherein said solvent comprisesat least about 82% by weight of said propylene glycol tertiary-butylether.
 21. The composition of claim 20, wherein said solvent comprisesno greater than about 90% by weight of said propylene glycol tertiarybutyl ether.
 22. The composition of claim 19, further comprising aneffective amount of a surfactant.
 23. A method of dyeing fabric,comprising treating the fabric to effect dyeing with a dye compositioncomprising a solution of a water-insoluble dye that is soluble in analiphatic glycol ether and is selected from the group consisting ofcationic dyes, dispersed dyes and vat dyes, dissolved in a solventcomprising propylene glycol tertiary-butyl ether (PTB) and/or propyleneglycol n-butyl ether (PNB) and up to about 18% by weight of water. 24.The method of claim 23, further comprising the step of drying saidfabric after said dyeing has been effected.
 25. The method of claim 23,wherein said solvent comprises at least about 82% by weight of saidpropylene glycol tertiary-butyl ether.
 26. The method of claim 25,wherein said solvent comprises no more than about 90% by weight of saidpropylene glycol tertiary-butyl ether.
 27. The method of claim 23,characterized in that said dye composition further comprises aneffective amount of a surfactant.
 28. A method of scouring raw woolcomprising scouring the wool with a composition comprising propyleneglycol tertiary-butyl ether (PTB) and up to about 18% by weight ofwater.
 29. A method of scouring raw wool comprising scouring the woolwith a composition comprising propylene glycol n-butyl ether (PNB) andup to about 18% by weight of water.
 30. A method of milling scoured rawwool, comprising milling the wool with a composition comprisingpropylene glycol tertiary-butyl ether (PTB) and up to about 18% byweight of water.
 31. A method of milling scoured raw wool, comprisingmilling the wool with a composition comprising propylene glycol n-butylether and up to about 18% by weight of water.